Subsequent Event	9 Months Ended
Sep. 30, 2020
Subsequent Events [Abstract]
Subsequent event	Subsequent eventOn October 27, 2020, we closed the sale of the shares pursuant to the Purchase Agreement, and issued 5,000,000 shares of our common stock to Merck at a purchase price of $200 per share, for proceeds of $1.0 billion. As a result, upon closing, we recorded $749.9 million in stockholders’ equity on our consolidated balance sheet, and will recognize the $250.1 million premium attributed to the Purchase Agreement in collaboration and license agreement revenues for the quarter and year ending December 31, 2020.

The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-URI http://asc.fasb.org/topic&trid=2122774

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 855
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6842918&loc=SL6314017-165662

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